In with of the following areas is wind a major erosional agent

It can easily pick up and move the fine, dry particles. It can damage natural fetures and human made structures. Erosion is the removal and transport of weathered material from one location to another. Weathering is the chemical and physical processes by which rocks on or near Earth’s surface break down and change. Weathering Changes occur every day to Earth’s rocks and surface features. 

Transcontinental railroad was the most effective way to travel.